Hi all. We have this late model Doosan light tower (I think about 2011-2012?) and 2 of the lights don't fire up. Before I start digging in with test lights I wanted to see if anyone could point me in the best direction to start. We put a new capacitor in it to make 60Hz and 120 volts (approximately). So I know the power is good. One set of lights just need love. Where is the best place to start testing? Thank you